A wind turbine generation apparatus generates electric power by rotating a main shaft connected to a blade that receives wind force, accelerating rotation of the main shaft by a gearbox, and then rotating a rotor of a generator. Each of the main shaft and the rotation shafts of the gearbox and the generator is rotatably supported by a rolling bearing, and an abnormality diagnostic device that diagnoses an abnormality of such a bearing is known.
Japanese Patent Laying-Open No. 2006-105956 (Patent Literature 1) discloses an abnormality diagnostic device that diagnoses an abnormality of a rotating component such as a bearing device. This abnormality diagnostic device is an abnormality diagnostic device that diagnoses an abnormality of a double-row tapered rolling bearing incorporated into a rolling bearing device for a railroad vehicle that relatively rotates with respect to a bearing housing, and includes a drive motor for rotationally driving the double-row tapered rolling bearing and a vibration sensor attached to the bearing housing. At the time of inertial rotation of the double-row tapered rolling bearing within the range of predetermined rotational speeds during power off of the drive motor, an abnormality of the double-row tapered rolling bearing is diagnosed based on a detection signal from the vibration sensor.
According to this abnormality diagnostic device, an abnormality of a rotating component can be diagnosed without disassembling the device in which the rotating component is incorporated, and an erroneous diagnosis under the influence of electric disturbance noise produced by rotation driving means can be prevented to allow a reliable abnormality diagnosis to be performed (see Patent Literature 1).